Pension Lump Sum vs Annuity Calculator

Pension lump sum vs annuity is one of the most important retirement decisions, and it is usually irreversible. A lump sum gives you a large one-time payment. An annuity gives you steady monthly income for life.

Compare them the right way, or the answer is meaningless. The comparison people reach for first is the wrong one: add up every annuity cheque you expect to receive, then grow the lump sum at some return rate, and see which number is bigger. That stacks money you received and spent against money you never touched. It is not a comparison at all, and it flatters whichever side you compound.

The correct question is: is the lump sum offer worth more or less than the stream of payments it replaces? Both sides get valued at the same date, using the same discount rate.

Present Value of Annuity = Σ (Annual Payment ÷ (1 + r)^year), for year = 1 to n

If that present value exceeds the lump sum offer, the pension is offering you less cash than the payments are worth, and the annuity wins on the maths.

The number that settles most of these decisions. Instead of picking a discount rate and hoping, ask what return the annuity itself is paying. That is the rate at which the payments discount back to exactly the lump sum offer, and this calculator computes it. If the annuity’s implied return is 6% and you genuinely believe you can earn 8%, take the lump sum. If it is paying 6% and you would put the money in bonds, take the annuity. It turns an argument about assumptions into one comparable number.

Key factors to compare:

Break-even analysis: The simple break-even is how many years of payments it takes to add up to the lump sum, ignoring any return on the money.

Break-even Years = Lump Sum ÷ Annual Annuity Payment

Treat it as a sanity check, not an answer. It gives the annuity no credit for the fact that a lump sum could have been earning something in the meantime, so it always makes the annuity look better than it is.

Worked example. A $500,000 lump sum offer against $2,500/month for an expected 25 years, discounted at 4%.

Discounting each of the 25 annual $30,000 payments back at 4% gives a present value of $468,662. The lump sum offer is $500,000, so the offer is worth about $31,000 more than the payments it replaces, and the annuity’s implied return is only 3.40%.

Now compare that to the arithmetic people usually do: $2,500 × 12 × 25 = $750,000 of payments, against $500,000 growing untouched at 4% for 25 years, which reaches $1,332,918. That framing declares the lump sum the winner “by $582,918”, eighteen times the real gap, and it would say so no matter how bad the offer was. The comparison method matters more than the inputs.

Investment return assumptions:

• Conservative: 4-5% annually (bonds, CDs)
• Moderate: 6-7% annually (balanced portfolio)
• Aggressive: 8-10% annually (stocks)

Pick the rate you actually expect to earn on the money, not the rate you would like to earn. A higher discount rate makes the annuity look worse, so an optimistic assumption quietly argues for the lump sum.

Practical considerations:

• If you have other guaranteed income (Social Security, rental income), a lump sum may give you more flexibility.
• If you have no other guaranteed income, the annuity provides a safety net.
• Consider your health and family longevity when estimating how long you will receive payments.
• Some pensions offer survivor benefits (reduced payments to your spouse after your death).

Tip: Many financial advisors suggest the annuity if you expect to live 20+ years in retirement and have no other guaranteed income sources.